Furnace for burning solid fuel



C; GEARING. FURNAGE PoR BURNING SOLID FUEL.

/Jivenozgi@ Y v ML' .WMM V UNITED STATES PATENT OEEICE.

CHARLESGEARING, OF PITTSBURG, PENNSYLVANIA, ASSIGNOR OF SEVEN- EIGHTHS TO SAMUEL HARPER, OF SAME PLACE, AND HENRYP. COOKE, LEWIS M. HOSEA, AND CHARLES F. HESSER, ALL OF CINCINNATI, OHIO.

FURNACE FOR BURNING SOLID FUEL.

SPECIFICATION forming part of Letters Patent No. 250,064, dated November 29, 1881.

Application filed March 26, 1881. (No model.)

To all whom it may concern Be it known that I, CHARLES GEARING, a citizen of the United States, residing at Pittsburg, Allegheny county, Pennsylvania, have invented new and useful Improvements in Furnaces for the Combustion of Solid Fuel for Heating Purposes, of which the following is a specicat-ion.

My invention is an improvement in fnrn aces 1o for the combustion of solid fuels for heating purposes, and is especially applicable to ironfnrnaces, steam-boilers, and other appliances used in the arts, its object being to convert the solid fuel into combustible gases by a continvnous process, with a view, preferably, to the immediate combustion of the gas as fuel for the ordinary uses, and producing a high and uniform heat and a perfect utilization of the combustible matterofthe coal without evolving 2o smoke, and with the maximum economy.

To this end my invention consists in the construction and arrangement of apparatus, as hereinafter more particularly described for carrying myinvention in to practical operation.

In the accompanying drawing, illustrating one form and application of my invention, the ligure is a sectional elevation of a gas-generator and its accompanying mechanism, and of a steamfboiler furnace, to which it is shown ap- 3o plied.

A designates the generator, and B an ordinary cylindrical return-flue boiler, to which it is applied. The generator consists, substantially, of a funnel-shaped chamber, C, with 3 5 walls of lire-brick or other refractory material, preferably formed, as shown, with an axis curving uniformly from the top to an approximately horizontal exit-throat, D, below, discharging into the usual combustion-chamber,

4o E, ofthe boiler-furnace. At the top of the generatorAis an opening, provided with aflan ged casing, F, projecting upward, closed above by a hinged cover, G, and any of the common devices may be employed for feeding coal autoL matically through the opening, or it may be fed by hand. Opening downward and through the top of the generator A, and arranged to discharge in the direction of its mean axis, is a hot-air pipe, H, connected by suitable pipes -'or iues with air-heath] g passages arranged at 5o any convenient point. in the furnace-Walls for utilizing the waste-heat. I have indicated in the drawing, by. dotted lines showing the general course, apassage, I, builtin the side Wall, and connecting' the air-pipe H With air-heating ilues I', arranged in the oor of boiler-furnace in rear of the fire-bridge. The airis drawn through the heating-dues and driven into the generating-chamber C by means of a jet of superheated steam discharged through asmaller pipe, J, in the pipe H. The steam-pipe J is connected with superheating-coils, also arranged in any convenient position in the furnace or generator walls Where the waste-heat may be utilized.

1 have shown the coils at K, extending from side to side in a recess formed in the rear wall ofthe generator A, and the connecting-pipe J' may be understood to extend thence through or outside of the side wall of the generator.

A hot-air pipe or channel, L, also extends into the chamber C, near the bottom, discharging in the direction of the exit-throat D. The

l heated airis also supplied by suitably-disposed passages from a convenient source of supplyfor example, the series of air-heating lines I?, also arranged in the bottom of the furnace in rear of the tire-bridge. The airis driven by a jet ot' superheated steam issuing through a pipe, J2, inserted in the pipe or passage L, as shown.

A channel, M, is arranged about midway in the height of the chamber C through yits front Wall, and another channel, N, is arranged at the bottom level, for purposes hereinafter explained, both being ordinarily kept closed by suit-able doors or stoppers, m u.

Other features of the construction will be noticed in the description of the operation, which is as follows: The generator being first heated in any convenient manner, and steam raised by a fire built in the bottom ofthe generator and upon the grate-bars O in the boiler-- furnace, the body of fuel is gradually increased by accessions from above until the exit-throat D is practically tilled withincandescentcoals, the draft of the stack being supplied through the generator-opcnings M N. As soon as steam is formed the blasts H and L arevstarted and the openingsMandNclosed. Thus the gases evolved from the fresh charges of coal at the top are, by the aid of the upper blast, H, and lower blast, L, caused to pass through the entire body of the incandescent and partly-spent coals in the exit-throat D, and heated and combined with the hot-air, and the water-gases, producing carbonio oxide and free hydrogen, which issue in a highly-heated condition from the generatorinto the combustion-chamber E of the boiler-furnace.

In order to effect a thorough combustion ot the gases thus produced, I provide a channel, I), preferably narrow, extending horizontally across the top of the exit-throat, and a similar channel, R, extending across the bottom, both opening rearward into the combustion-chamber E. These channels are for the discharge of heated air above and'lbelow the current of gases to aid their combustion. They may be supplied from heating-'fines built in the side walls of the boiler-furnace, as indicated for the upperchannel,P,bythedottedlilies. TheopeningsP and R may heextended quite around the throatD, so as to surround the outgoing current of gases with a thin envelope of hea-ted air. It will be readily seen that'the passa ge of the current of gases through the throat will tend to draw the air through the passages I) lt. For a similar purpose an air-discharge, S,is arranged across and in the bridge-wall, communicating with air-heating filles I3. The bridge-wall is inclined to the rear, and thus a similar effect is produced by the currents of gases passing over itin drawing the air through the passage S. Thus the gases discharged from the generator, being intensely heated and in a state of preliminary combustion, are thoroughly ignited by the accessions ot'heated air through the passages I, R, and S in the furnace under the boiler.

In case any stoppage occurs in the passage of the coalr downward through the generator, a poker may be inserted through the passages M and N, and by means of the latter the spent coal and ash may be shoved hack ward to the grates O and fall into the closed ash-pit beneath.

A supplemental air-passage, T, is provided, connecting the air-channel P directly with the open air. By means of a suitable valve it may be opened, when necessary, for the purpose of admitting colder air beneath the boiler as a partial protection from too intense heat at that point.

The throat D is constructed of refractory tiles or fire-brick, so as to admit a convenient renewal in case of injury from heat.

By this process a perfect combustion of the carbon of solid fuels is effected, and the remaining ash is in the form of fine particles, commonly called breeze/7 which are carried by the blasts into the combustion-chamber of the furnace and dropped through the grate into the ash-pit. The degree of heat may be regulated at will by graduating the force ot' the blasts, suitable valves being provided for the purpose in the steam-pipes J and J2.

It will be obvious that my invention may be applied to any existing furnace with but little alteration inthe latter, and also that in ironmills or other places where a number of furnaces are used a single producer may be used, and the gases conveyed by pipes to several furnaces at the same time or to a holder; but in general it is found preferable to use a generator adapted to the capacity of the furnace and use the gas immediately on its production.

Having described my invention, I claim and Adesire to secure by Letters Patentl. In a furnace, the combination of the retort-chamber having closed walls extending downward and terminating at the lower end in an exit-throat, arranged to discharge in an approximately horizontal direction into the combustion-chamber of a boiler or other furnacewith top and bottom hot-air and steamblast pipes or fines openingthrough the walls of the retort-chamber, and arranged to dischargehighly-heated airand su perheated steam into the retort-chamber at thc top and 'bottom portions of the fresh charge of coal, thereby forcing the gases evolved from thefresh charges through and over the incandescent coked portions at the exit-throat of the retort-chamber and into the combustion-chamber of the boiler or other furnace.

2. In a furnace, the combination of the retortchamber C, uniformly curved from the top to its bottom exit-throat, which opens into the combustion-chamber E of a boiler or other furnace, with the top and bottom hot-air pipes,H and L, and top and bottom steam-pipes, J and J 2, all arranged to discharge highly-heated air and steam into the retort-chamber at its top and bottom portions, to force the gases evolved at the top ofthe fresh charge of coal through the incandescent fuel in the exit-throat of the retort-chamber into the combustion-chamber of the boiler or other furnace, substantially as described.' 1

3. The combination,`with the retort-chamber having the exit-throat D, opening into the combustion-chamber E of the boiler or other furnaces, of the top and bottom hot-air and steam pipes discharging into the retortchamber, and the channels P and R, extending across the top and bottom of the exit-throat D and opening into the combustion-chamber E, and both connected with hot-air ues, substantially as described.

In testimony whereof'I have hereunto set my hand in the presence of two subscribing witnesses.

CHARLES GEARING. Witnesses:

C. l?. DooLIT'rLn, L. M. HosEA.

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